Stationary induction apparatus



April 13, 1926.

L. H. BURNHAM STATIONARY INDUCTION APPARATUS Filed Oct. 25. 1920 2 Sheets-$11961'. l

Inventor: Locke HJSuFnham,

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STTIONARY INDUCTION APPARATUS Filed Oct. 23 1920 2 Sheets-Sheet 2 www,

. r f 1 n l n l l,

Locke H Bufnharn,

. which increases the cooling effects had from Patented pr. 1,3, 1926.

UNITED STATES i 1,580,811 PATENT oFFICE.

LOCKE H. BURNHAM, OF PITTSFIELD,'MASSACHUSETTS, ASSIGNOR'TO GENERAIELEC- i '.E'RIC COMPANY, A CORPORATION OF NEW YORK.

STATIONARY INDUCTION .APPARATS.

Application med october 2s, mao.,` `serial 1re. 41.151,00?.`

To all whom t may concern." Y

Be it knownthat I, Looxn I-I. BURNHAM, a citizen ofthe United States, residing at Pittsfield, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Stationary Induction Apparatus, of which the following is a specilication. y

My invention relates to stationary induction apparatus, such as transformers, autotransformers, some reactances and the like, which are cooled by' forcing a cooling me-y dium over the windings. More particularly my invention relates to stationary induction apparatus of the shell type in whiih blasts of air as the cooling medium are forced or circulated over the windings.

The object of this invention is to provide angimproved arrangement-of parts which is economically and readily manufactured and the circulated air so as,` to exceed those had with the prior arrangements;V

In shell type transformers, andsimilar electrical apparatus which are cooled by air blasts, it has been found that what may be termed straight lin-e paths for the course of the `cooling air are most satisfactoryconsidered from the standpoint of length of uninterrupted service. As a result straight andsimple paths for the air blasts characterize ,the design of all modern electrical Vapparatus of this type.

It is known, however, that straight unimr peded air channels permit the most rapid movement of the air at the centre of the channel While that nearest the walls of the channel is apparently stagnant or bound by surface tension with the consequence that, in air blast electrical `apparatus having straight line air passages, the maximumcooling eect is not had from a given volume of air circulated.

In the practice of my invention, the heat absorbing capacity of a given volume of' air circulated is `greatly enhanced by the provision of a battling means which does not alter the straight line character of th-e air passages' but which does Vcause the air in the passages to eddy and break upV the stagnant and surface-bound portions of the air columns therein thereby avoiding local hot spots in the winding.

For a more complete understanding of the nature and objects ofmy invention refer-.

:ence should be had to the following detailed description taken in connection with the accompanying drawings in which:

Fig. l is a vertical section through a shell type transformer construct-ed to embody my invention,l Fig. 2 is a :fragmentary vertical section, `in a plane at right angles to the plane of Fig. 1; while Fig. 3 is a horizontal section of the transformer taken on the line zzz-a: looking in the direction of the arrows in F ig. 2.

Referring now to the drawings, 10 represents ashell type core composed of horizontally disposed laminations of magnetic material having a central leg 11 surrounded by windings 12.

The windings 12 areV shown as composed Y of so-called pan-cake coils 13 which are .supported and encased in insulating boxmgsrll and 15. The core itself surmounts The insulating boxing 14 surrounds theleg 11 jof the core and holds the coils 12 in proper spaced relation therefrom, while the insulating boxing 15 has rectangular Y y 1 a `base'l which at the place of installation fits over an air chamber whence is received projecting upper and lower ends 2O and 21 respectively which not only serve to support and insulate the windings but to guide the air currents as they pass from the base 16 into the housing 17 whence theytind ,egress through the valved structure shown at 18.

The sides of this boxing 15 are shown as formed to extend through the windows in the core 10, and accordingly fit snugly against and about the boxing 14. f

The coils 12 in the boxing 15 are preferably divided into groups by means of vertically disposed separators, as shown at 22.

`The coils themselves are spaced apart by suitably interposed insulatingk spacers 23 which may be of any convenient type, those shown being sometimes termed wavy spacers.

In order to battle the air currents passing up between the spacers 23 in accordance with my invention so as to cause them to eddy but without changingthe generally straight line character of passages thus formed, I provide air deflectors 24 which are secured to the upper end of the boxing 15 and propoints a in Fig. vl.

ters these channels for some distance.

elliptical pieces 26 which meet the deflectors 24 thus closing in the sides.

Just after emerging from the side chan-Y nels in theboxingl5,V the air is deflected and caused to eddyby the deflectors 24:. These deilectors 2a are-:disposed close to the exits of the side channels, the distance being suiiiciently small to cause-the eddying and turbulence of-the air under the deflectors to be communicated effectively to they air inside the'channelsl; yThis eddying or turbulence of the air within the-'channels breaks up-tlie stagnant surface-bound air adheringto the insulation of the-coils 13 and tothe spacers 23, thus more efficiently absorbing heat which might otherwise cause hotspots asy atr the The deiiectors 2a should not, of course, be so close to the exits of the channels as to obstruct too much the flow of cooling airthrough'tlie channels oi' the decreasefin the iiow of-air would offset the advantage due toits turbulence.- The proper and most e'fiicientrelative. sizes and locations of parts are approximately Vindicated in the drawing and can readily be determined in any particular case by simple tests.

The deflectors l2li arealso eective in increasing the cooling of tliecoil surfaces exposed in the"inteimediate-oi centralv channels which are over thefcentral'core leg 11V and where the flow of-air is impeded by this core leg.y As thev air froin'the side channels strikes the defiectors, it is not-only caused to eddy as has been described but some of it at least is deflected back toward the exits of the intermediate channels and actually eny This increases the absorptionv of heat at thispoint also, the deflected air later emerging from thel channelsv with the air flowing through these channels from below.

Having now described an embodiment of my invention which is at present the `best means lnowii to me for carrying the same into effect, I would have it understood that this is merely illustrative and that l do not ymeanv to be limited thereby to the precise details shown, nor restricted in the choice of recognized equivalents except as defined in my claims hereunto annexed.

Vhat I claim as new and desire to secure by LettersfPatent of the United States, is

l. A stationary induction apparatus having windings disposed in spaced relation to form Ventilating passages to conduct a cool- -ing medium, and deflectors for deflecting the cooling medium leaving the side Vportions of the exits of said .passagest to direct it toward the intermediate portions ofsaid -exits,'said deflectors being arranged sufficiently close to said exits to cause said deflected cooling medium to increase the disturbance of said medium in the intermediate portions of said passages', whereby the cooling .effect of said medium is increased.

2. 4A stationary induction apparatus having windings disposed in spaced relation to form Ventilating vpassages to vconduct-a cooling medium, andl curved deflectorsfor defleeting the cooling medium leaving the side portions of the exitsof said-passages to direct it toward the intermediate portionsfof said exits, said deflec'tors being arranged surficientiy close tosaid .exits =to cause said deflected'cooling medium-5to increase the disturbance `of said medium inthe intermediate portions of-said passages,-whereby thev cooling effect ofsaid-medium is increasedw 3. A stationaryinduction apparatus comi piising'a shell-type coi'e having windings l surrounding a leg thereof and disposedv in spaced relation therealong,riniier and/outer insulating .members vdisposed 4aboutv said windingsand arranged to provid-e veiitilat- Y ing 1 passages therethrough, i and vdeflec'ting means secured lto said outer member andarranged adjacent to the-exitsV offsaidpassages* `to cause said medium vto eddy as it emerges from the passages, said-defiectingf means 'being sufficiently close-to saidexits tocause the eddyin'gof saidmediui'nto produce tui'- bulence in the medium within said passages before emerging therefrom.

4. A stationary induction apparatusv comprising .a shell-type core having windings surrounding a leg thereof and disposed` in spaced'relation therealong,inner and outer insulating members disposed about "said` windingsl and arranged to provide ventilating passages therethrough, and curved de'- flectors secured to said outer member and varranged.toproject over theV exits'of Said passages and to meet the same at'their outer edges to cause` said mediumfto eddyV 4as -it' emerges from the passages," said'deflectorsbeing sufficiently close to said exits lto cause the eddying of said medium to produce tur-Y bulence 4in the medium` within lsaid passages before emerging therefrom. v

5. A stationary induction apparatus having windings disposed in spaced relation to form Ventilating passages to conduct a cooling medium,and' means for deflecting Vthe. cooling medium leaving the side portions of the exits of said passages to'direct it toward the intermediate portions? of said.-A exits,'

whereby the coolingeffect of said medium is increased.

6. -A stationary induction' apparatus having windings disposed in spaced'relation to between said windings into channels, and means for deiiecting the cooling medium leaving the channels at the side portions of said passages to direct it toward the exits of the intermediate channels, whereby the cooling effect of said medium is increased.

7. A stationary induction apparatus having windings disposed in spaced relation to form Ventilating passages to conduct a cooling medium, and defiectors projecting over portions of the exits of said passages and arranged sufficiently close to said exits to increase the disturbance of said medium within the passages, whereby the cooling effect of said medium is increased.

8. A stationary induction apparatus hav ing windings disposed in spaced relation to form Ventilating passages to conduct a cooling medium, and curved deliectors projecting over portions of the exits of said passages and arranged suliciently close to said exits to increase the disturbance of said medium within the passages, whereby the cool ing effect of said medium is increased.

9. A stationary induction apparatus having windings disposed in spaced relation to forni Ventilating passages to conduct a cooling medium, means for separating the spaces between said windings into channels, and deflectors extending in front of the side channels from the outer edges of said passages, said delectors being suiiciently close to the exits of said side channels to increase the disturbance of said medium within the passages, whereby the cooling ell'ect of said medium is increased.

In Witness whereof, I have hereunto set my hand this 20th day of October, 1920.

LO CKE H. BURNHAM. 

